Mineral lubricating oil compositions



United States Patent "ice 3,175,974

Patented Mar. 30, 1965 1 2 3 175 974 octyl, isooctyl, nonyl, isononyl, decyl, undecyl, dodecyl, MINERAL LUBRICAzHNG OIL CGMPOSITIONS tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl,

ehanmiit Rai and John E Bmunwarth Crystal Lake, In octadecyl, nonadecyl, and eicosyl radicals in the aliphatic signers to The Pure on company, Chicago, In. a serles. The aryl groups include phenyl, naphthyl, and b1- corpomfien 0g 0M0 phenyl; the aralkyl groups include benzyl, phenylethyl,

No Drawing. Filed Aug. 31, 1961, Ser. No. 135,154 5 the alkaryl g p include y y y and the like;

3 Claims. (Cl. 252-47) the cycloalkyl radicals may be cyclopropyl, cyclobutyl,

cyclopentyl, and cyclohexyl radicals; the alkoxy radicals This invention relates to a new class of chemical cominclude methoxy, ethoxya hexoxy; and the halo radicals i pounds characterized as bis(2-benzothiazolyl)dialkyl sulelude ch) and bmmo.

fides. More particularly, this invention relates to the dis- 10 Species f compounds coming within the f i g covery that compounds characterized as bis-2(benzod fi iti are:

sulfides are effective oxidatlon and cor 1, bis zo yndimethyl Sulfide y 2,2-bis(2-benzothiazol l)dieth lsulfide It 18 known in the art that mercaptobenzothlazoles are Y Y antioxidants for highly refined oils. One derivative therei'i, g y tp p Sulfide of, namely di(benzothiazolyl)disulfide is a particularly f fs(2'benzoth}azolyl)d}buty1Sulfide effective antioxidant. Also, mercaptoarylthiazoles are l Sulfide used in the art as corrosion inhibitors b1s(2'benZOth1aZ1y1)dlhexyl Sulfide In a copendmg applicatlon 56118.1 No. 116,934, filed 8 b P June 14, 1961, there is described a series of new anti- 20 4 ,15 P Y yl ulfide oxidants comprising di(2- benzothiazolyl)alkanes, and y f Y l y Sulfide more particularly, compounds such as 1,1-bis(2-benzoly wctyl ulfide thiazolyl)methane and 1,8-bis(2-benzothiazolyl)octane. f -P ly syl sulfide These compounds are useful for preventing the oxidative 'lsopropyl's 'butyl'lal y1) methyl deterioration of liquid systems at elevated temperatures. sulfide The compounds of the present invention are sulfur The compounds of this invention can be prepared by a analogues of the compounds in said copending applicanumber of different methods, including the condensation tion, and contrary to expectations, are oxidation and corof an o-aminothiophenol with a dibasic thioalkyl acid in rosion inhibitors. the presence of a catalyst such as a polyphosphoric acid.

Accordingly, it becomes a primary object of this mven- This reaction is illustrated by thefollowing:

UHF 125 c 2 /C-CHrGH1CHgS--CH CH C SH H 0 olypigsiphorlc N i CH3- 'CH3 0 CHg-GH1CH1-S-OH3C Hg-C tion to provide a new class of chemical compounds com- In order to illustrate but not limit the invention, the

prising bis(2-benzothiazolyl)dialkyl sulfides and deriva- 4 following examples are given. tives thereof.

Another object of this invention is to provide oxidation EXAMPLE 1 inhibitors comprising bis(2-benzothiazolyl)dialkyl sulfides.

Another object of this invention is to provide composi- AS a Specific embodiment of this invention, 2

tions containing and processes employing oxidation in- 5 hibitors comprising bis(2-benzothiazolyl)dialkyl sulfides.

A further object of this invention is to provide corrosion-inhibiting compositions containing bis(2-benzothiazolyl) dialkyl sulfides.

These and further objects of this invention will be described or become apparent as the specification proceeds.

The new oxidation inhibitors of this invention are characterized by having a bis(2-benzothiazolyl)dialkyl sulfide nucleus and are represented by the formula (benzothiazolyl)diethyl sulfide, was prepared by reacting 0.2 mole of o-aminothiophenol with 0.1 mole of 3,3- thiodipropionic acid (ester or nitrile) in the presence of 150 g. of polyphosphoric acid, at a temperature of 125 C. The resulting intermediate product was decomposed with ice, and washed with water, sodium bicarbonate solution, and water. The resulting, raw product was crystallized from alcohol. The purified product had a melting point of 158.5 C., and its structure was as follows:

wherein n and m are the same or different integers from 1 s to 12 and R and R are hydrogen, or the same or different hydrocarbon radicals containing from 1 to 20 carbon atoms. R and R can be hydrogen, or alkyl, aryl, aralkyl, The effectiveness of this compound as a corrosion inalkaryl, cycloalkyl alkoxy or halo radicals, including hibitol' Was demonstrated y subjecting Several Samples methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, containing well known and eifective corrosion inhibitors amyl, isoamyl, t-amyl, hexyl, isohexyl, heptyl, isoheptyl, and also samples containing the compound of Example 3 I to the bulk oil oxidation test. The results are as follows:

Table I BULK OIL OXIDATION TEST-EFFECT OF ADDITIVES ON METAL CORROSION Priinol D is a proprietary name for a super refined oil of naphthenic character having the following characteristics: Sp. gr. of 28.3; flash, F. of 430; fire, F. of 495; vis;. F. at60,000 S.U.S.; vis. 100 F. of 366.7 S.U.S.; vis. 130 F. of 164.9 S.U.S.; vis. 210 F. of 53.5 S.U.S.; Saybolt color of +30; pour, F. of "-25; av. mol. wt. of 430; C.R. of 0.3; VI of 77; percent sulfur less than 0.05; neut. No. (1948) less than 0.03; N wt. percent-less than 0.02; C Wt. percent-86.2; H wt. percent-43.6, prepared from naphthenic crude sources and refined by repeated H 50 treatment and/or drastic hydrogenation. This oil is merely illustrative, and other fluid systems, such as lubricating oils generally, waxes, emulsions, cutting oils, gear oils, greases, polish compositions, reaction systems, water purification systems and the like can be benefited by incorporation of the compounds of this invention.

The Bulk Oil oxidation test is Method 5308.4 of Central Test Method Standard No. 791, dated December 15, 1955, entitled Corrosiveness and Oxidation Stability of Light Oils (metal strips). Since this method is a standard corrosiveness and oxidation stability test known in the art, it is only necessary to refer to the method number.

EXAMPLE 11 About 0.2 mole of 2-amino-4-methylthiophenol and 0.1 mole of 4,4-thiiodibutyric acid are reacted in the presence of 150 g. of polyphosphoric acid at about 130 C. for two hours. The reaction mixture is decomposed by the addition of crushed ice and the resulting organic phase is washed with water, sodium bicarbonate solution, and finally with water again. The product is taken up in alcohol and crystallized therefrom. The product (in partially purified form) has the following structure:

EXAMPLE III About 0.3 mole of 2-amino-4-ch1orothiophenol and about 0.15 mole of 5.5'-thiodipentan0ic acid are reacted under the conditions of Example I to form 3,3-dichloro- 4,4-di(2-benzothiazo1yl)dibutyl sulfide.

The compounds of this invention may be used singly, or in mixture in liquid or solid systems at low concentrations, preferably within the range of about 0.1 to 3.0% by wt. for service under conditions wherein it is desired to inhibit oxidation. The liquid or solid system may comprise any system used under conditions where it is desired to inhibit oxidation, and in which a small but eifective quantity of the compounds of this invention can be incorporated. The compounds of this invention :are generally water-insoluble, but are soluble .in organic solvents, hydrocarbons, mineral oils, synthetic lubricants and rubber. Accordingly, the compounds of this invention can be incorporated in water systems by the addition of an emulsifier or carrier liquid which is water-soluble or water-miscible. A particular application would be the use in a solid or semi-solid system, such as plastics or rubber, wherein it is desired to inhibit oxidation. Another application would be in testing the effectiveness of oxidation inhibitors wherein the compounds of this invention may be used to otiset the negative catalytic action of the inhibitors.

The polyphosphoric acid used as a catalyst in preparing the compounds of this invention comprise solutions of phosphorus pentoxide in phosphoric acid. These solutions generally contain about by wt. of phosphorus pentoxide in the phosphoric acid, and the particular acid used to illustrate this invention contained this amount of phosphorus pentoxide. Other polyphosphoric acids containing between about 60 to of phosphorus pentoxide in phosphoric acid may be used as the catalyst or hydrochloric acid may be used. Since the general nature or" this reaction and the manipulations for conducting same are known, no further explanation is necessary. The product of the reaction is a solid and is readily separated by water dilution or other known techniques. Having thus described the invention, the only limitations attaching thereto appear in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A mineral lubricating oil composition comprising a major portion of mineral lubricating oil and about 0.1 to 3.0 wt. percent of an antioxidant of the formula wherein n has a value of 1 to 12, m has a value of 1 to 12, and R and R are substituents of the group consisting of hydrogen, C -C alkyl, phenyl, naphthyl, biphenyl, benzyl, phenylethyl, tolyl, xylyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, hexoxy, chloro and bromo.

2. A mineral lubricating oil composition consisting essentially of a major portion of a mineral lubricating oil and about 0.1 to 3.0 wt. percent of 2,2'-bis(2-benzothiazolyl) diethyl sulfide.

3. A mineral lubricating oil composition consisting essentially of a major portion of a mineral lubricating oil and about 0.1 to 3.0 wt. percent of 3,3-bis(2-benzothiazolyl) dipropyl sulfide.

References Cited by the Examiner UNITED STATES PATENTS 2,111,990 3/38 Reed et al. 44-63 2,154,097 4/39 Loane 25239l 2,218,283 10/40 Fuller 252-47 2,568,472 9/51 Trautrnan 252-336 2,942,003 6/60 Copeland 260304 2,963,433 12/60 Little et al. 252391 3,004,034 10/61 DAmico 260304 OTHER REFERENCES Musgrave et al.: Chem. Abstracts, volume 50, column 1251c (1953).

Zubarovskii: Chem. Abstracts, volume 46, column 6641 (1952).

Chem. Abstracts: 5th Decennial Index, page 18008 (1960).

DANIEL E. WYMAN, Primary Examiner.

DUVAL T. MCCUTCHEN, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,175 ,974 March 30, V 1965 Charanjit Rai et a1.

It is hereby certified-that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, linesi- 54 to 59, for that portion of the formula reading:

' 4 C(CHZ)3 read -/C (CH2) 3 S column 3, line 62 for "5.5-' read Signed and sealed this 17th day of August 1965.

(SEAL) Aucst:

EDWARD J. BRENNER Commissioner of Patent-5 ERNEST W. SWIDER Attcsting Officer UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,175 ,974 March 50, 1965 Charanj it R-ai et al.

It is hereby certified-that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected be1o* Column 3, linea 54 to 59, for that portion of the formula reading:

/ C(CHZI3 S read I/C (CH2) 3 S column 3, line 62, for "5.5-' read 5, 5

Signed and sealed this 17th day of- August 1965.

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents ERNEST W. SWIDER Attesting Officer 

1. A MINERAL LUBRICATING OIL COMPOSITION COMPRISING A MAJOR PORTION OF MINERAL LUBRICATING OIL AND ABOUT 0.1 TO 3.0 WT. PERCENT OF AN ANTIOXIDANT OF THE FORMULA 